Making of Ella

Specular - I've rendered this pass by turning off all the color maps and setting the diffuse to black (yep, using the built in pass rendering doesn't seam to like working with the SSS materials) I used this pass to control the level of highlights at different parts of the image.
Falloff - Rendered the same way, only specular was turned off and I threw a falloff map in the reflection slot. This pass served to fake the "peach fuzz" effect at certain edges. When used correctly, it slightly gives an "oily" feeling to the skin.
Hair - I've rendered out each and every piece of hair separately so that I'll have very good control over the colors of the hair in photoshop.
Occlusion pass - this pass helped a bit to add more depth to the geometry. I wrote a tutorial on how I use it.
Hair occlusion - Same as above. In order for the hair to render out correctly in the occlusion pass, you need to select your hair, under the "MR parameters" turn on "apply mr shader" and place your occlusion material there (you need to be in MR prim mode).
Peach fuzz - This pass was rendered out for extra skin details that mainly show in the full resolution. I used a mask to make it show up only in areas it usually shows up like on the the lip or the chin.

That's it, after combining all the passes together, I went through some color correcting and some local fine tuning and this is the result (50% resolution). I hope this was informative and interesting for you.
(c) Ziv Qual, www.zivcg.com